Compatible with AT&T CLP99487 and CLP99587 expandable cordless phone systems sold separately- DECT 6.0 technology offers crystal-clear calls- LCD screen provides at-a-glance information- Compatible with caller ID and call waiting features- Caller ID announce speaks the name of incoming callers, so youFTll know whoFTs on the line when you pick up- Call waiting/caller ID service required from your local telephone company- Connect-to-cell function lets you pair the handset with your mobile phone, so you wonFTt have to worry about dropped calls or weak cellular signals- Compatible with Siri, S Voice and Google Now for flexible use- Intercom between the handset and base allows simple communication between offices and rooms- 200-number phonebook provides easy access to your contacts list